Digital Image Watermark Algorithm Based On PDF417 And Lifting Wavelet

With the rapid development of Internet technology, the emergence of e-commerce and the vast of commercial multimedia have made the media security and identification a very particularly issue. In recent years, digital watermarking technology as a new protection program of digital products has more and more broad prospects. Since the wavelet transformation has some advantages better than DCT, and JPEG2000 which is the new image compressing standard substitutes wavelet transform for DCT. Therefore, digital watermarking algorithm based on wavelet transform has aroused researchers'enormous interest.In this paper, the theories of digital watermarking technology are introduced in detail in this paper firstly, focusing on the classic analysis of the existing algorithms, as well as their advantages and disadvantages, also discussing the common attack and corresponding countermeasure in the digital watermark application. Secondly, describing the coding and decoding pricniples of PDF417 2D-barcode and RS error-correcting codes. The basic knowledge of lifting wavelet and its application in digital image watermarking are introduced. Finally, digital watermarking algorithm of multiresolution traditional wavelet transform is studied, and the algorithm of digital image watermarking based on PDF417 and lifting wavelet is proposed, combining the characteristics of RS error correcting code (ECC) of PDF417 with that's of lifting wavelet. Namely, coding original watermark based on the principle of PDF417, and scrambling it under a key in order to generating two value watermark image which is difficult to crack. Decomposing and reconstructing original image using lifting wavelet technology in the process of embedding and extracting watermark in the low frequency band. The experimental results show that this algorithm is more robust and invisible to the common image of resistance attacks, but also has avoided the image size requirements of traditional wavelet transform, meanwhile, has improved computational speed. Therefore, the algorithm is a good practicability for protecting digital products.